Britannica Sources used in this answer

How is the specific heat of water measured?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Joseph Black Joseph Black, detail of an engraving by J. Rogers after a portrait by Sir Henry Raeburn

The Scottish scientist Joseph Black founded the concept of specific heat in the 18th century after observing that equal masses of different substances require varying amounts of heat to undergo the same temperature change.1

The specific heat of water is defined as the quantity of heat required to raise the temperature of one gram of water by one degree Celsius, a value established as one calorie (or approximately 4.186 joules).12

In practice, heat capacities and specific heats are measured using a calorimeter, a device designed to measure heat exchange during physical or chemical processes. For solid materials, a common technique is the "drop method," where a known mass of a substance at a high temperature is added to a known mass of water at a lower temperature. By measuring the final equilibrium temperature of the mixture, the heat absorbed by the water and the container can be calculated, allowing for the determination of the substance's specific heat.234